<template>
	<view>
		<my-search @click="gotoSearch"></my-search>
		<view class="scroll-view-container">
			
		      <!-- 左侧的滚动视图区域 -->
		      <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
		        <block v-for="(item, i) in cateList" :key="i">
		          <view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}</view>
		        </block>
		      </scroll-view>
			  
		      <!-- 右侧的滚动视图区域 -->
		      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
		        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
		          <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
				  <!-- 动态渲染三级分类的列表数据 -->
				  <view class="cate-lv3-list">
				    <!-- 三级分类 Item 项 -->
				    <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
				      <!-- 图片 -->
				      <image :src="item3.cat_icon"></image>
				      <!-- 文本 -->
				      <text>{{item3.cat_name}}</text>
				    </view>
				  </view>    
		        </view>
		      </scroll-view>
		    </view>
	</view>
</template>

<script>
	// 导入自己封装的 mixin 模块
	import badgeMix from '@/mixins/tabbar-badge.js'
	
	export default {
		// 将 badgeMix 混入到当前的页面中进行使用
		mixins: [badgeMix],
		
		data() {
			return {
				// 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
				wh: 0,
				// 分类数据列表
				cateList: [],
				// 当前选中项的索引，默认让第一项被选中
				active: 0,
				// 二级分类列表
				cateLevel2: [],
				// 滚动条距离顶部的距离,切换一级分类后滚动条重新置顶
				scrollTop: 0,
				
				/* a:Math.floor(Math.random()*100) */
				
				icons : [
				  "https://img13.weikeimg.com/data/uploads/2015/08/17/147333976155d14e4067b66.jpg",
				  "https://www.shinerayad.com/upfile/attached/2017651626313141208.jpg",
				  "https://photo.16pic.com/00/01/39/16pic_139811_b.jpg",
				  "https://img.phb01.com/d/file/p/2020/01-02/4b89b3a050046a0d95d537f4dc95c58a.jpg",
				  "https://img.zhisheji.com/uploads/0315/155258657049192897.jpg",
				  "https://img.zhisheji.com/uploads/0315/155258657198235485.jpg",
				  "https://img.zhisheji.com/uploads/0315/155258656910281369.jpg",
				  "https://upload.shejihz.com/2019/11/c6b3fcf6c7eea55378caea64d8a21d0b.jpg",
				  "https://5b0988e595225.cdn.sohucs.com/images/20190624/5c06cdc88eb7485eb213251f84f03f77.jpeg",
				  "https://www.colostar.cn/wp-content/uploads/2021/01/905c0b86e8e51be.jpg",
				  "https://www.colostar.cn/wp-content/uploads/2021/03/image-13.jpg",
				  "https://img.ixintu.com/download/jpg/20200815/8119603a705cd27421fb92262aed2c71_512_512.jpg%21con",
				  "https://i.52112.com/icon/jpg/256/20210730/125276/5351672.jpg",
				  "https://www.zygj.net/User_Files/image/News/2017/06/zygj.net-170608-1033-6.jpg",
				  "https://img1.baidu.com/it/u=2176917313,189393526&fm=253&fmt=auto&app=138&f=JPEG?w=715&h=475",
				  "https://img0.baidu.com/it/u=193543168,1545090043&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=500",
				  "https://img2.baidu.com/it/u=844466962,884810851&fm=253&fmt=auto&app=138&f=JPEG?w=360&h=360",
				  "https://img2.baidu.com/it/u=2552528128,2898981021&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=300",
				  "https://img0.baidu.com/it/u=1203938082,3896580687&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=500",
				  "https://img2.baidu.com/it/u=184886958,2979673193&fm=253&fmt=auto&app=138&f=PNG?w=285&h=286",
				  "https://img0.baidu.com/it/u=739718625,31376804&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=350",
				  "https://img0.baidu.com/it/u=3116240301,2749416576&fm=253&fmt=auto&app=138&f=JPEG?w=693&h=336",
				  "https://img2.baidu.com/it/u=3058205630,2116403296&fm=253&fmt=auto&app=138&f=JPEG?w=420&h=320",
				  "https://img1.baidu.com/it/u=524436501,4249141025&fm=253&fmt=auto&app=138&f=JPEG?w=450&h=394",
				  "https://img1.baidu.com/it/u=1483847531,845531491&fm=253&fmt=auto&app=138&f=JPEG?w=300&h=300",
				  "https://img0.baidu.com/it/u=3548166050,458694330&fm=253&fmt=auto&app=138&f=JPEG?w=580&h=370",
				  "https://img1.baidu.com/it/u=2858099763,3882558402&fm=253&fmt=auto&app=138&f=JPEG?w=580&h=386",
				  "https://img2.baidu.com/it/u=2235659010,679026651&fm=253&fmt=auto&app=138&f=JPEG?w=430&h=280",
				  "https://img0.baidu.com/it/u=2067319320,4024916255&fm=253&fmt=auto&app=138&f=JPEG?w=355&h=360",
				],
				
			};
		},
		onLoad() {
			// 获取当前系统的信息
			const sysInfo = uni.getSystemInfoSync()
			// 为 wh 窗口可用高度动态赋值
			this.wh = sysInfo.windowHeight - 50
			
			// 调用获取分类列表数据的方法
			this.getCateList()
		},
		methods:{
			// 获取分类列表数据的方法
			async getCateList() {
			    // 发起请求
			    const { data: res } = await uni.$http.get('/api/public/v1/categories')
			    // 判断是否获取失败
			    if (res.meta.status !== 200) return uni.$showMsg()
			    // 转存数据
			    this.cateList = res.message
				// 为二级分类赋值
				this.cateLevel2 = res.message[0].children
			
				//因cat_icon的值不能访问，改变成使用data中的值
				/* this.cateLevel2[0].children.forEach((child, index) => {
				  child.cat_icon = this.icons[Math.floor(Math.random()*12)];
				}); */
				
				
				this.cateLevel2.forEach((category, index) => {
				  category.children.forEach((child, childIndex) => {
				    /* child.cat_icon = this.icons[Math.floor(Math.random()*this.icons.length)]; */
					child.cat_icon = child.cat_icon.replace('dev','web')
				  });
				});
				
			},
			
			// 选中项改变的事件处理函数
			activeChanged(i){
				this.active = i
				
				// 为二级分类列表重新赋值
				this.cateLevel2 = this.cateList[i].children
				
				this.cateLevel2.forEach((category, index) => {
				  category.children.forEach((child, childIndex) => {
				    /* child.cat_icon = this.icons[Math.floor(Math.random()*this.icons.length)]; */
					child.cat_icon = child.cat_icon.replace('dev','web')
				  });
				});
				
				
				
				// 让 scrollTop 的值在 0 与 1 之间切换
				this.scrollTop = this.scrollTop === 0 ? 1 : 0
			},
			
			// 点击三级分类项跳转到商品列表页面
			gotoGoodsList(item3) {
			  uni.navigateTo({
			    url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
			  })
			},
			gotoSearch(){
				uni.navigateTo({
					url:'/subpkg/search/search'
				})
			}
		},	
	}
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;

  .cate-lv3-item {
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
    }
  }
}
</style>
